1. Field of the Invention
This invention relates to a clamping tool or power wrench having a driving power source and a power shaft engaging, for example, with a bolt, nut or the like connected to said driving power source by way of a speed reduction mechanism.
2. Description of the Prior Art
This invention relates to a clamping tool or power wrench of electromotive, hydraulic and pneumatic type and the like which clamping a torque set bolt, usual bolt and the like to a clamps member.
In the known clamping tools or power wrenches of this type, the rotation of a driving power source is transmitted by way of a speed reduction device to a power shaft and clamping a body such as a bolt, nut, etc. is fitted to and rotated together with a power shaft to thereby tightly clamp said clamped body. In such a construction, however, when a tightening torque arrives at a predetermined level, the reaction force thereof is directly exerted on a worker carrying the tool to increase his fatigue. Some time, the reaction force even goes beyond the grasping force of the worker, which forces him to drop the tool to damage the same or even causes human accidents.